Many widely known recombinant DNA techniques involve replicating or amplifying DNA. One such example is the polymerase chain reaction (PCR). During PCR, a thermostable DNA polymerase cycles repeatedly between low and high temperatures (e.g., 55° C. and 95° C.). The total period of time spent at the high temperature depends upon the total number of cycles, the duration of the high temperature step of each cycle, and the ramp speed (i.e., the speed at which the thermocycler switches between the steps of each cycle). Although these DNA polymerases are highly thermostable, they tend to become inactive at high temperatures over time. Furthermore, these enzymes may also be inactivated by dilution into aqueous environments with sub-optimal concentration of cofactors or sub-optimal pH levels, and the presence of chemical or biological inhibitors in the reaction mixtures.
One way of stabilizing an enzyme is to add a stabilizing agent, such as a surfactant. Surfactants, or detergents, are surface-active compounds that stabilize the interface between the active form of an enzyme and the liquid environment in which they are contained. The activity of Taq DNA polymerase has been stabilized by the addition of nonionic detergents, such as Tween 20. In some applications, however, Tween 20-stabilized DNA polymerases have low efficiencies of amplification or lead to the amplification of non-specific products. There is a need, therefore, for detergents that improve the stability of thermostable DNA polymerases in solution, and particularly detergents that improve enzyme stability without imparting any of the disadvantages of currently used detergents.